DE 10145006 discloses a slot milling disc comprising an integrated disc-shaped portion and a hub-formed portion, which is arranged at the centre of the disc-shaped portion and which is adapted to be connected to a rotatable shaft at a bearing surface having a recess or spline at the rear end of the hub portion. The disc has coolant channels having a confined cross section and extending radially within the milling disc to outlet openings in the bottom of chip spaces separating adjacent projections in the peripheral surface of the disc provided with cutting inserts. The coolant channels provide an efficient cooling of the cutting inserts when this is needed during operation of the slot milling disc. The slot milling disc may however be improved in terms of evacuation of cuttings or chips, especially when cutting comparatively narrow and deep slots in a work piece.
The main challenge in slot or groove milling is usually chip evacuation. Chip issues often harm production efficiency, lower component quality or cause tool breakage, especially when milling narrow and deep slots/grooves.
There are slot milling discs being formed as thin discs having a thickness of only about 2-10 mm, which around their outer peripheries are provided with a number of cutting edges and which are primarily used for cutting grooves in various work pieces. On one of their side surfaces these discs have a bearing surface closest to their centre axis which is arranged to be facing and clamped towards a mounting surface in an end of a rotatable mounting shaft. The still unpublished European patent application No.14164374.2 discloses a slot milling disc in which the attachment means is configured to force a bearing surface of the disc towards a mounting surface at an end surface of a mounting shaft and flushing fluid channels having a confined cross-section extend within the milling disc from an inlet opening in the bearing surface to an outlet opening in the peripheral surface of the disc located in a chip space in the form of a concaveness in the peripheral surface between adjacent projections which are each provided with a cutting edge. This means that flushing fluid jets may also for thin such discs, which may be used to mill deep slots/grooves, be directed to reach into such slots/grooves without any risk of hitting the work piece beside the slot/groove machined, so that the efficiency of the flushing will be substantially improved with respect to flushing fluid jets directed towards the milling disc and the work piece from the outside.